1. Field of the Invention
The present invention relates generally to bottles and more specifically to a two-piece stopper for retaining items in a neck of a bottle.
2. Discussion of the Prior Art
Stoppers are used throughout laboratories to seal vessels such as flasks, bottles or tubes. The stoppers are often employed with multiple holes to allow the insertion of tubes for receiving and dispensing vessel contents or for thermometers. Stoppers are usually fabricated from rubber, and are sold as either solid or with holes (1-hole, 2-hole, or 3-hole). Solid stoppers can have holes bored or drilled to the correct size and quantity in the absence of pre-formed holes. Because of the multitude of possible hole sizes, quantities, and stopper size variations, a large inventory of different stoppers is often needed.
Several types of improved stoppers have been proposed—for example, U.S. Pat. No. 3,282,457 to Sirois (1966) discloses a stopper which has pre-formed holes capped by protruding plugs which can be removed via tearing and later reinserted if needed; commonly marketed today under the trademark “Twistit”. However, if the hole size changes, the plugs will not properly seal. Once removed, the small plugs can be easily misplaced.
Forcefully inserting and removing glass tubing has also been a major problem as it can take significant force. This force can cause glass breakage, which can injury the user. If a mercury type thermometer is used, this can be an especially harmful and a costly concern. According to the CRC Handbook of Laboratory Safety, 5th Edition, by A. Keith Furr, “Inserting glass tubing into stoppers or flexible plastic or rubber hoses is the source of one of the most common laboratory accidents with glass. Usually the cause is trying to force the tubing into the hole with no hand protection.”
To help remedy this hazard, Parvin revealed through U.S. Pat. No. 2,802,587 (1957) a stopper which has tapered hole(s). Having a tapered hole can reduce the force necessary to insert or remove glass tubing. However, the tapered hole feature of this design is likely to limit the minimum possible spacing, and thus quantity and size of holes allowed in a stopper. Additionally, this design limits any possibility of plugging previously employed holes.
Finally, International Publication No. WO 03/095318 to Zeni discloses a composite stopper made of synthetic materials. Patent publication no. 20040238479 to Caswell discloses a stopper for bottle. U.S. Pat. No. 8,714,383 to Corson discloses a compound bung for wine and spirits.
Accordingly, there is a clearly felt need in the art for a two-piece stopper, which provides a better seal between an inner perimeter of a neck of a container and the two-piece stopper than that of the prior art, and decreases the chance of breaking glass tubing retained in the two-piece stopper.